We supply slick drill collars, spiral drill collars and non-magnetic drill collars; their sizes are from 3-1/8 to 11 inches. Besides the drill collars in the table below, we can supply other drill collars at customers' request.

Drill Collars

Drill Collor Number*

Outside Diameter,
in.

Inside Diameter,
in.

Length,
ft

Approximate Weight,
lb/ft

Typical Bending
Strength Ratio

NC 23-31

3-1/8

1-1/4

30

22

2.57:1

NC 26-35 (2-3/8 IF)

3-1/2

1-1/2

30

27

2.42:1

NC 31-41 (2-7/8 IF)

4-1/8

2

30 or 31

34

2.43:1

NC 35-47

4-3 /4

2

30 or 31

47

2.58:1

NC 38-50 (3-1/2 IF)

5

2-1/4

30 or 31

54

2.38:1

NC 44-60

6

2-1/4

30 or 31

83

2.49:1

NC 44-60

6

2-13 /16

30 or 31

76

2.84:1

NC 44-62

6-1/4

2-1/4

30 or 31

91

2.91:1

NC 46-62 (4 IF)

6-1/4

2-13 /16

30 or 31

84

2.63:1

NC 46-65 (4 IF)

6-1/2

2-1/4

30 or 31

100

2.76:1

NC 46-65 (4 IF)

6-1/2

2-13 /16

30 or 31

93

3.05:1

NC 46-67 (4 IF)

6-3 /4

2-1/4

30 or 31

109

3.18:1

NC 50-70 (4-1/2 IF)

7

2-1/4

30 or 31

118

2.54:1

NC 50-70 (4-1/2 IF)

7

2-13 /16

30 or 31

111

2.73:1

NC 50-72 (4-1/2 IF)

7-1/4

2-13 /16

30 or 31

120

3.12:1

NC 56-77

7-3 /4

2-13 /16

30 or 31

140

2.70:1

NC 56-80

8

2-13 /16

30 or 31

151

3.02:1

6-5/8 API Reg

8-1/4

2-13 /16

30 or 31

162

2.93:1

NC 61-90

9

2-13 /16

30 or 31

196

3.17:1

7-5/8 API Reg

9-1/2

3

30 or 31

217

2.81:1

NC 70-97

9-3 /4

3

30 or 31

230

2.57:1

NC 70-100

10

3

30 or 31

243

2.81:1

8-5/8 API Reg

11

3

30 or 31

300

2.84:1

*The number connection (NC ) is an API connection with the V- .065 thread form with a V- .038R thread root radius. The first two digits are the pitch diameter of the thread and the last two digits are the outside diameter of the drill collar.